There is a phrase which you sometimes come across in country
districts even nowadays, which sums up a good deal of what he
might have tried to say. Farmers use it in Ireland, as praise or
compliment, saying, "So-and-so has a Word. He will do what
he promised."

Lancelot tried to have a Word. He considered it, as the
ignorant country people still consider it, to be the most valuable
of possessions.

But the curious thing was that under the king-post of keeping
faith with himself and with others, he had a contradictory nature
which was far from holy. His Word was valuable to him not only
because he was good, but also because he was bad. It is the bad
people who need to have principles to restrain them. For one
thing, he liked to hurt people. It was for the strange reason that
he was cruel, that the poor fellow never killed a man who asked
for mercy, or committed a cruel action which he could have
prevented. One reason why he fell in love with Guenever was
because the first thing he had done was to hurt her. He might
never have noticed her as a person, if he had not seen the pain
in her eyes.

People have odd reasons for ending up as saints. A man who
was not afflicted by ambitions of decency in his mind might simply
have run away with his hero's wife, and then perhaps the tragedy
of Arthur would never have happened. An ordinary fellow, who
did not spend half his life torturing himself by trying to discover
what was right so as to conquer his inclination towards what was
wrong, might have cut the knot which brought their ruin.

'Jenny, all my life I have wanted to do miracles. I have
wanted to be holy. I suppose it was ambition or pride or some
other unworthy thing. It was not enough for me to conquer the
world—I wanted to conquer heaven too. I was so grasping that
it was not enough to be the strongest knight—I had to be the best
as well. That is the worst of making day-dreams. It is why I
tried to keep away from you. I knew that if I was not pure, I
could never do miracles. And I did do a miracle, too: a splendid
one. I got a girl out of some boiling water, who was enchanted
into it. She was called Elaine. Then I lost my power. Now
that we are together, I shall never be able to do my miracles any
more.'

He did not like to tell her the full truth about Elaine, for he
thought that it would hurt her feelings to know that he had come
to her as the second.

'Why not?'

'Because we are wicked.'

'Personally I have never done a miracle,' said the Queen,
rather coldly. 'So I have less to regret.'

'But, Jenny, I am not regretting anything. You are my miracle,
and I would throw them overboard all over again for the sake of
you. I was only trying to tell you about the things I felt when I
was small.'

'Well, I can't say I understand.'

'Can't you understand wanting to be good at things? No, I
can see that you would not have to. It is only people who are
lacking, or bad, or inferior, who have to be good at things. You
have always been full and perfect, so you had nothing to make up
for. But I have always been making up. I feel dreadful sometimes,
even now, with you, when I know that I can't be the best
knight any longer.'

Aberforth Dumbledore: On the night Lord Voldemort went to Godric's Hollow to kill Harry, and
Lily Potter cast herself between them, the curse rebounded. When that happened, a part of Voldemort's soul lached itself onto the only living thing it could find. Harry himself.

There's a reason Harry can speak with snakes. There's a reason he can
look into Lord Voldemort's mind. A part of Voldemort lives inside him.

[Harry Potter] is kind of an interesting character, because he’s not really good; and we find out that’s because [he has a piece of Voldemort] in him.

What that means is that to be good, truly good […] you have to be able to understand malevolence. And in order to be able to understand malevolence so that you can withstand it, you have to understand that part of you that’s malevolent. Because if you don’t, you’re naive. And if you’re naive, you’re easy pickings.

That’s a Jungian idea, that part of personality development is to understand your shadow. The shadow is those things about you that you do not want to admit to.

I think that you cannot have proper respect for yourself until you know that you’re a monster. Because you won’t act carefully enough if you think, “I’m a nice person, I’d never do anyone any harm.” You’re no saint, you can be sure of that, and the harm that you can do people can come in many, many ways. And so, if you regard yourself as harmless, inoffensive, nice … well, why do you have any reason to be careful? You’re like a teddy bear sitting on a shelf; even if you throw it at someone, no-one’s going to get hurt. But that isn’t what you’re like, because you’re a human being; and human beings are vicious creatures. And there’s utility in knowing that.

What’s interesting about [Harry Potter] is that he’s touched by evil. And that means that he’s an embodiment of what Jung would regard as someone who’s integrated the shadow. And without that capacity he isn’t able to communicate, say, with snakes. And that’s not so good because, since there are snakes, its not such a bad idea to know how to communicate with them.

[...] Harry could stand up against Voldemort and understand him and speak his language, because he was infected by him to some degree.